Light metal alloy



Patented Oct. 4, 1932 UNITED STATES PATENT OFFICE,

RAYMOND J. NORTON, OF WAS HINGTON, DISTRICT OE COLUMBIA, AS SIGNOR TO AMERI- CAN MAGNESIUM METALS CORPORATION, OF PITTSBURGH, PENNSYLVANIA, A

CORPORATION 01' DELAWARE LIGHT METAL ALLOY N0 Drawing. Application filed November 28, 1930, Serial No. 498,912. Renewed April 23, 1932.

This invention relates-to improvements in light metal alloys and particularly to an improved magnesium beryllium alloy.

The advantage of beryllium as an alloying component with other metals has heretofore.

been appreciated. It has been proposed, for example, to incorporate small amounts of beryllium with aluminum to form a binary and with aluminum and copper to form a ternary alloy. It has furthermore been found that by a special heat treatment the aluminum beryllium alloys may be considerably improved as to hardness and breaking strength.

It has also been proposed to produce magnesium beryllium alloys. This type of alloy would present decided advantages in view of its great lightness.

The method of producing magnesium beryllium alloys sists essentially of reducing a double fluoride of beryllium to the molten condition and adding to this a certain quantity of molten magnesium. The theory of the process is that a certain quantity of the magnesium reduces 1; ide.

:. beryllium fluoride with the formation of beryllium and ma esium fluoride. The quantity of magnesium added, therefore, is equal to that to be contained in the final alloy and that required to reduce the beryllium hal- Prior art disclosures on this indicate that the operation was carried out in an iron vessel and that the end product presented a decided tendency to stick to the iron.

The present method represents a simplified process of preparing a magnesium beryllium alloy by combining the pure metals out of contact with iron, or other alloying sub stances, and substantiall out of contact with air. The invention will be more fully understood from a consideration of the specific lndthod of making up the desired material.

An alloy of magnesium and beryllium has been made up by treating a predetermined -quantity of pure magnesium with the desired amount of beryllium. -In tests actually run 2.4 grams of ma esium were used with approximately .3 o a gram of beryllium. 1 The analysis of the beryllium indicated that the metal was in a high state of purity. The

analysis of the magnesium indicated very heretofore proposed conslight traces of aluminum and iron. In making up the alloy a strong iron bomb was lined with a refractory of magnesium oxide which was baked at a high temperature for approximately two hours. In the bomb was placed the quantities of magnesium and beryllium stated above, after which the bomb was hermetically sealed.

The material in the bomb was then heated for a coming up period for about two hours at 950 C. It was then held at between 950 and 1000 C. for five hours.

It'will be noted that inasmuch as the bomb was hermetically sealed and inasmuch "as the magnesium forms a stable oxide in a nitride, the heat treatment may be considered to be carried out under non-oxidizing conditions. It is also to be noted that the heat treatment is carried out below the melting point of beryllium, which is generally considered to be about 1280 C. After the described treatments, that is to say after heatin ,in

excess of 900 for prolonged period of time, I

a single billet of metal was removed from the bomb..' This material looked considerabl like magnesium but was quite definitely harder pure magnesium.

In order to establish the homogeniety of thematerial, small pieces were cut off each end of the billet and dissolved in an equal quantity of hydrochloric' acid. After dissolution of the two ends the solution was treated with ammonium chloride and ammonia and allowed to stand for a period of two hours, during which time beryllium hydroxide was precipitated. It was found that the quantities of beryllium in each of the pieces were substantially the same, indicating the homogeneous dispersion and/or difi'usion of the beryllium in the magnesium. i

It appears that the present method may be similar in mechanics of operation to the diffusion of one metal in another, as is found for example in calorizing and chromizing treatments. In any event, it has beelifound and more resistant to corrosion than each of these pieces were that a new metallic compound of magnesium and beryllium may be made 'up which predistinguishing from the two metal components, and that'this compound may be obtained without the necessity of reducing the berylliumto the'molten condition. In view 5 of the conditions of thetreatment it is also apparent that the characteristics of the final, metallic substance are not dependent u on the formation of an iron beryllium alloy or, due to the fact that the operation is carried out out of contact with iron, the incorporation of this metal in the final alloy is precluded.

It will be appreciated therefore that the present process provides a method of readily and simply o taining an improved alloy or metallic compound of magnesium and beryllium. The process involves only a simple heat treatment at relatively low temperatures and insures the formation of a nal product which is characterized by desirable physical properties. Therefore, while ,a specific process has been described, it is to be understood that this is given merely as an example of one methodo incorporat- 5 ing the principles disclosed herein and the invention is not to be considered restricted to the particular method of 'treatment'except. as such restrictions are clearly imposed by' the appended claims. 4 30. I claim:

1. The method of makin an alloy of magnesium and beryllium whic comprises heating substantially pure magnesium and beryllium outof contact with air and above the 35 melting point of magnesium for a prolonged period o time. p

'2. The method oi making an alloy of magnesium and beryllium comprising heating the substantially pure metals out of contact with 40 air for a'prolonged period at a temperature above the melting point of magnesium but below the melting point of beryllium. 3L The method of making an alloy'of magnesium and beryllium which comprises heat- 45 ing substantially pure magnesium and beryllium, above the melting int of magnesium for a prolonged period 0 time, out of contact with air in a vessel, the portion of which is in contact with the magnesium and beryllium so being formed of material other than iron.

n,testimony whereof I aflix m si ature.

- RAYMOND J. OR ON. 

